251. Semiconducting and ferromagnetic behavior of sputtered Co-doped TiO[sub 2] thin films above room temperature.
- Author
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Park, Wan Kyu, Ortega-Hertogs, Ricardo J., Moodera, Jagadeesh S., Punnoose, Alex, and Seehra, M. S.
- Subjects
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THIN films , *SPUTTERING (Physics) - Abstract
We have investigated Co-doped TiO[sub 2] thin films grown by reactive co-sputtering. X-ray diffraction showed a single phase polycrystalline rutile structure, without any segregation of Co into particulates within the instrumental resolution limit. The atomic content of Co ranged from 1% to 12%. The temperature dependence of resistivity showed an extrinsic semiconducting behavior. From optical absorption measurements, the band gap E[sub g] ≈ 3.2 5 ± 0.0 5 eV was found, independent of the Co concentration, and in agreement with a literature value. Room temperature M-H loops showed a ferromagnetic behavior for Co content higher than 3%. The magnetic moment per Co atom was estimated to be about 0.94 µ[sub B], suggesting a low spin configuration of Co ions. The temperature dependence of remanent magnetization revealed a Curie temperature higher than 400 K for Co content of 12%. [ABSTRACT FROM AUTHOR]
- Published
- 2002
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